1 /* SSA operands management for trees.
2 Copyright (C) 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GCC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING. If not, write to
18 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
19 Boston, MA 02110-1301, USA. */
23 #include "coretypes.h"
28 #include "diagnostic.h"
29 #include "tree-flow.h"
30 #include "tree-inline.h"
31 #include "tree-pass.h"
35 #include "langhooks.h"
36 #include "ipa-reference.h"
38 /* This file contains the code required to manage the operands cache of the
39 SSA optimizer. For every stmt, we maintain an operand cache in the stmt
40 annotation. This cache contains operands that will be of interest to
41 optimizers and other passes wishing to manipulate the IL.
43 The operand type are broken up into REAL and VIRTUAL operands. The real
44 operands are represented as pointers into the stmt's operand tree. Thus
45 any manipulation of the real operands will be reflected in the actual tree.
46 Virtual operands are represented solely in the cache, although the base
47 variable for the SSA_NAME may, or may not occur in the stmt's tree.
48 Manipulation of the virtual operands will not be reflected in the stmt tree.
50 The routines in this file are concerned with creating this operand cache
53 The operand tree is the parsed by the various get_* routines which look
54 through the stmt tree for the occurrence of operands which may be of
55 interest, and calls are made to the append_* routines whenever one is
56 found. There are 4 of these routines, each representing one of the
57 4 types of operands. Defs, Uses, Virtual Uses, and Virtual May Defs.
59 The append_* routines check for duplication, and simply keep a list of
60 unique objects for each operand type in the build_* extendable vectors.
62 Once the stmt tree is completely parsed, the finalize_ssa_operands()
63 routine is called, which proceeds to perform the finalization routine
64 on each of the 4 operand vectors which have been built up.
66 If the stmt had a previous operand cache, the finalization routines
67 attempt to match up the new operands with the old ones. If it's a perfect
68 match, the old vector is simply reused. If it isn't a perfect match, then
69 a new vector is created and the new operands are placed there. For
70 virtual operands, if the previous cache had SSA_NAME version of a
71 variable, and that same variable occurs in the same operands cache, then
72 the new cache vector will also get the same SSA_NAME.
74 i.e., if a stmt had a VUSE of 'a_5', and 'a' occurs in the new operand
75 vector for VUSE, then the new vector will also be modified such that
76 it contains 'a_5' rather than 'a'. */
79 /* Structure storing statistics on how many call clobbers we have, and
80 how many where avoided. */
84 /* Number of call-clobbered ops we attempt to add to calls in
85 add_call_clobbered_mem_symbols. */
86 unsigned int clobbered_vars
;
88 /* Number of write-clobbers (VDEFs) avoided by using
89 not_written information. */
90 unsigned int static_write_clobbers_avoided
;
92 /* Number of reads (VUSEs) avoided by using not_read information. */
93 unsigned int static_read_clobbers_avoided
;
95 /* Number of write-clobbers avoided because the variable can't escape to
97 unsigned int unescapable_clobbers_avoided
;
99 /* Number of read-only uses we attempt to add to calls in
100 add_call_read_mem_symbols. */
101 unsigned int readonly_clobbers
;
103 /* Number of read-only uses we avoid using not_read information. */
104 unsigned int static_readonly_clobbers_avoided
;
108 /* Flags to describe operand properties in helpers. */
110 /* By default, operands are loaded. */
113 /* Operand is the target of an assignment expression or a
114 call-clobbered variable. */
115 #define opf_def (1 << 0)
117 /* No virtual operands should be created in the expression. This is used
118 when traversing ADDR_EXPR nodes which have different semantics than
119 other expressions. Inside an ADDR_EXPR node, the only operands that we
120 need to consider are indices into arrays. For instance, &a.b[i] should
121 generate a USE of 'i' but it should not generate a VUSE for 'a' nor a
123 #define opf_no_vops (1 << 1)
125 /* Operand is an implicit reference. This is used to distinguish
126 explicit assignments in the form of GIMPLE_MODIFY_STMT from
127 clobbering sites like function calls or ASM_EXPRs. */
128 #define opf_implicit (1 << 2)
130 /* Array for building all the def operands. */
131 static VEC(tree
,heap
) *build_defs
;
133 /* Array for building all the use operands. */
134 static VEC(tree
,heap
) *build_uses
;
136 /* Set for building all the VDEF operands. */
137 static VEC(tree
,heap
) *build_vdefs
;
139 /* Set for building all the VUSE operands. */
140 static VEC(tree
,heap
) *build_vuses
;
142 /* Bitmap obstack for our datastructures that needs to survive across
143 compilations of multiple functions. */
144 static bitmap_obstack operands_bitmap_obstack
;
145 /* Set for building all the loaded symbols. */
146 static bitmap build_loads
;
148 /* Set for building all the stored symbols. */
149 static bitmap build_stores
;
151 static void get_expr_operands (tree
, tree
*, int);
153 /* Number of functions with initialized ssa_operands. */
154 static int n_initialized
= 0;
156 /* Statement change buffer. Data structure used to record state
157 information for statements. This is used to determine what needs
158 to be done in order to update the SSA web after a statement is
159 modified by a pass. If STMT is a statement that has just been
160 created, or needs to be folded via fold_stmt, or anything that
161 changes its physical structure then the pass should:
163 1- Call push_stmt_changes (&stmt) to record the current state of
164 STMT before any modifications are made.
166 2- Make all appropriate modifications to the statement.
168 3- Call pop_stmt_changes (&stmt) to find new symbols that
169 need to be put in SSA form, SSA name mappings for names that
170 have disappeared, recompute invariantness for address
171 expressions, cleanup EH information, etc.
173 If it is possible to determine that the statement was not modified,
174 instead of calling pop_stmt_changes it is quicker to call
175 discard_stmt_changes to avoid the expensive and unnecessary operand
176 re-scan and change comparison. */
180 /* Pointer to the statement being modified. */
183 /* If the statement references memory these are the sets of symbols
184 loaded and stored by the statement. */
189 typedef struct scb_d
*scb_t
;
191 DEF_VEC_ALLOC_P(scb_t
,heap
);
193 /* Stack of statement change buffers (SCB). Every call to
194 push_stmt_changes pushes a new buffer onto the stack. Calls to
195 pop_stmt_changes pop a buffer off of the stack and compute the set
196 of changes for the popped statement. */
197 static VEC(scb_t
,heap
) *scb_stack
;
199 /* Return the DECL_UID of the base variable of T. */
201 static inline unsigned
202 get_name_decl (tree t
)
204 if (TREE_CODE (t
) != SSA_NAME
)
207 return DECL_UID (SSA_NAME_VAR (t
));
211 /* Comparison function for qsort used in operand_build_sort_virtual. */
214 operand_build_cmp (const void *p
, const void *q
)
216 tree e1
= *((const tree
*)p
);
217 tree e2
= *((const tree
*)q
);
220 u1
= get_name_decl (e1
);
221 u2
= get_name_decl (e2
);
223 /* We want to sort in ascending order. They can never be equal. */
224 #ifdef ENABLE_CHECKING
225 gcc_assert (u1
!= u2
);
227 return (u1
> u2
? 1 : -1);
231 /* Sort the virtual operands in LIST from lowest DECL_UID to highest. */
234 operand_build_sort_virtual (VEC(tree
,heap
) *list
)
236 int num
= VEC_length (tree
, list
);
243 if (get_name_decl (VEC_index (tree
, list
, 0))
244 > get_name_decl (VEC_index (tree
, list
, 1)))
246 /* Swap elements if in the wrong order. */
247 tree tmp
= VEC_index (tree
, list
, 0);
248 VEC_replace (tree
, list
, 0, VEC_index (tree
, list
, 1));
249 VEC_replace (tree
, list
, 1, tmp
);
254 /* There are 3 or more elements, call qsort. */
255 qsort (VEC_address (tree
, list
),
256 VEC_length (tree
, list
),
262 /* Return true if the SSA operands cache is active. */
265 ssa_operands_active (void)
267 return cfun
->gimple_df
&& gimple_ssa_operands (cfun
)->ops_active
;
271 /* VOPs are of variable sized, so the free list maps "free buckets" to the
284 Any VOPs larger than this are simply added to the largest bucket when they
288 /* Return the number of operands used in bucket BUCKET. */
291 vop_free_bucket_size (int bucket
)
293 #ifdef ENABLE_CHECKING
294 gcc_assert (bucket
>= 0 && bucket
< NUM_VOP_FREE_BUCKETS
);
298 return (bucket
- 13) * 8;
302 /* For a vop of NUM operands, return the bucket NUM belongs to. If NUM is
303 beyond the end of the bucket table, return -1. */
306 vop_free_bucket_index (int num
)
308 gcc_assert (num
> 0 && NUM_VOP_FREE_BUCKETS
> 16);
310 /* Sizes 1 through 16 use buckets 0-15. */
313 /* Buckets 16 - NUM_VOP_FREE_BUCKETS represent 8 unit chunks. */
314 num
= 14 + (num
- 1) / 8;
315 if (num
>= NUM_VOP_FREE_BUCKETS
)
322 /* Initialize the VOP free buckets. */
325 init_vop_buckets (void)
329 for (x
= 0; x
< NUM_VOP_FREE_BUCKETS
; x
++)
330 gimple_ssa_operands (cfun
)->vop_free_buckets
[x
] = NULL
;
334 /* Add PTR to the appropriate VOP bucket. */
337 add_vop_to_freelist (voptype_p ptr
)
339 int bucket
= vop_free_bucket_index (VUSE_VECT_NUM_ELEM (ptr
->usev
));
341 /* Too large, use the largest bucket so its not a complete throw away. */
343 bucket
= NUM_VOP_FREE_BUCKETS
- 1;
345 ptr
->next
= gimple_ssa_operands (cfun
)->vop_free_buckets
[bucket
];
346 gimple_ssa_operands (cfun
)->vop_free_buckets
[bucket
] = ptr
;
350 /* These are the sizes of the operand memory buffer which gets allocated each
351 time more operands space is required. The final value is the amount that is
352 allocated every time after that. */
354 #define OP_SIZE_INIT 0
356 #define OP_SIZE_2 110
357 #define OP_SIZE_3 511
359 /* Initialize the operand cache routines. */
362 init_ssa_operands (void)
364 if (!n_initialized
++)
366 build_defs
= VEC_alloc (tree
, heap
, 5);
367 build_uses
= VEC_alloc (tree
, heap
, 10);
368 build_vuses
= VEC_alloc (tree
, heap
, 25);
369 build_vdefs
= VEC_alloc (tree
, heap
, 25);
370 bitmap_obstack_initialize (&operands_bitmap_obstack
);
371 build_loads
= BITMAP_ALLOC (&operands_bitmap_obstack
);
372 build_stores
= BITMAP_ALLOC (&operands_bitmap_obstack
);
373 scb_stack
= VEC_alloc (scb_t
, heap
, 20);
376 gcc_assert (gimple_ssa_operands (cfun
)->operand_memory
== NULL
);
377 gcc_assert (gimple_ssa_operands (cfun
)->mpt_table
== NULL
);
378 gimple_ssa_operands (cfun
)->operand_memory_index
379 = gimple_ssa_operands (cfun
)->ssa_operand_mem_size
;
380 gimple_ssa_operands (cfun
)->ops_active
= true;
381 memset (&clobber_stats
, 0, sizeof (clobber_stats
));
383 gimple_ssa_operands (cfun
)->ssa_operand_mem_size
= OP_SIZE_INIT
;
387 /* Dispose of anything required by the operand routines. */
390 fini_ssa_operands (void)
392 struct ssa_operand_memory_d
*ptr
;
396 if (!--n_initialized
)
398 VEC_free (tree
, heap
, build_defs
);
399 VEC_free (tree
, heap
, build_uses
);
400 VEC_free (tree
, heap
, build_vdefs
);
401 VEC_free (tree
, heap
, build_vuses
);
402 BITMAP_FREE (build_loads
);
403 BITMAP_FREE (build_stores
);
405 /* The change buffer stack had better be empty. */
406 gcc_assert (VEC_length (scb_t
, scb_stack
) == 0);
407 VEC_free (scb_t
, heap
, scb_stack
);
411 gimple_ssa_operands (cfun
)->free_defs
= NULL
;
412 gimple_ssa_operands (cfun
)->free_uses
= NULL
;
414 while ((ptr
= gimple_ssa_operands (cfun
)->operand_memory
) != NULL
)
416 gimple_ssa_operands (cfun
)->operand_memory
417 = gimple_ssa_operands (cfun
)->operand_memory
->next
;
422 VEC_iterate (tree
, gimple_ssa_operands (cfun
)->mpt_table
, ix
, mpt
);
426 BITMAP_FREE (MPT_SYMBOLS (mpt
));
429 VEC_free (tree
, heap
, gimple_ssa_operands (cfun
)->mpt_table
);
431 gimple_ssa_operands (cfun
)->ops_active
= false;
434 bitmap_obstack_release (&operands_bitmap_obstack
);
435 if (dump_file
&& (dump_flags
& TDF_STATS
))
437 fprintf (dump_file
, "Original clobbered vars: %d\n",
438 clobber_stats
.clobbered_vars
);
439 fprintf (dump_file
, "Static write clobbers avoided: %d\n",
440 clobber_stats
.static_write_clobbers_avoided
);
441 fprintf (dump_file
, "Static read clobbers avoided: %d\n",
442 clobber_stats
.static_read_clobbers_avoided
);
443 fprintf (dump_file
, "Unescapable clobbers avoided: %d\n",
444 clobber_stats
.unescapable_clobbers_avoided
);
445 fprintf (dump_file
, "Original read-only clobbers: %d\n",
446 clobber_stats
.readonly_clobbers
);
447 fprintf (dump_file
, "Static read-only clobbers avoided: %d\n",
448 clobber_stats
.static_readonly_clobbers_avoided
);
453 /* Return memory for operands of SIZE chunks. */
456 ssa_operand_alloc (unsigned size
)
460 if (gimple_ssa_operands (cfun
)->operand_memory_index
+ size
461 >= gimple_ssa_operands (cfun
)->ssa_operand_mem_size
)
463 struct ssa_operand_memory_d
*ptr
;
465 if (gimple_ssa_operands (cfun
)->ssa_operand_mem_size
== OP_SIZE_INIT
)
466 gimple_ssa_operands (cfun
)->ssa_operand_mem_size
467 = OP_SIZE_1
* sizeof (struct voptype_d
);
469 if (gimple_ssa_operands (cfun
)->ssa_operand_mem_size
470 == OP_SIZE_1
* sizeof (struct voptype_d
))
471 gimple_ssa_operands (cfun
)->ssa_operand_mem_size
472 = OP_SIZE_2
* sizeof (struct voptype_d
);
474 gimple_ssa_operands (cfun
)->ssa_operand_mem_size
475 = OP_SIZE_3
* sizeof (struct voptype_d
);
477 /* Go right to the maximum size if the request is too large. */
478 if (size
> gimple_ssa_operands (cfun
)->ssa_operand_mem_size
)
479 gimple_ssa_operands (cfun
)->ssa_operand_mem_size
480 = OP_SIZE_3
* sizeof (struct voptype_d
);
482 /* Fail if there is not enough space. If there are this many operands
483 required, first make sure there isn't a different problem causing this
484 many operands. If the decision is that this is OK, then we can
485 specially allocate a buffer just for this request. */
486 gcc_assert (size
<= gimple_ssa_operands (cfun
)->ssa_operand_mem_size
);
488 ptr
= (struct ssa_operand_memory_d
*)
489 ggc_alloc (sizeof (struct ssa_operand_memory_d
)
490 + gimple_ssa_operands (cfun
)->ssa_operand_mem_size
- 1);
491 ptr
->next
= gimple_ssa_operands (cfun
)->operand_memory
;
492 gimple_ssa_operands (cfun
)->operand_memory
= ptr
;
493 gimple_ssa_operands (cfun
)->operand_memory_index
= 0;
495 ptr
= &(gimple_ssa_operands (cfun
)->operand_memory
496 ->mem
[gimple_ssa_operands (cfun
)->operand_memory_index
]);
497 gimple_ssa_operands (cfun
)->operand_memory_index
+= size
;
502 /* Allocate a DEF operand. */
504 static inline struct def_optype_d
*
507 struct def_optype_d
*ret
;
508 if (gimple_ssa_operands (cfun
)->free_defs
)
510 ret
= gimple_ssa_operands (cfun
)->free_defs
;
511 gimple_ssa_operands (cfun
)->free_defs
512 = gimple_ssa_operands (cfun
)->free_defs
->next
;
515 ret
= (struct def_optype_d
*)
516 ssa_operand_alloc (sizeof (struct def_optype_d
));
521 /* Allocate a USE operand. */
523 static inline struct use_optype_d
*
526 struct use_optype_d
*ret
;
527 if (gimple_ssa_operands (cfun
)->free_uses
)
529 ret
= gimple_ssa_operands (cfun
)->free_uses
;
530 gimple_ssa_operands (cfun
)->free_uses
531 = gimple_ssa_operands (cfun
)->free_uses
->next
;
534 ret
= (struct use_optype_d
*)
535 ssa_operand_alloc (sizeof (struct use_optype_d
));
540 /* Allocate a vop with NUM elements. */
542 static inline struct voptype_d
*
545 struct voptype_d
*ret
= NULL
;
548 int bucket
= vop_free_bucket_index (num
);
551 /* If there is a free operand, use it. */
552 if (gimple_ssa_operands (cfun
)->vop_free_buckets
[bucket
] != NULL
)
554 ret
= gimple_ssa_operands (cfun
)->vop_free_buckets
[bucket
];
555 gimple_ssa_operands (cfun
)->vop_free_buckets
[bucket
] =
556 gimple_ssa_operands (cfun
)->vop_free_buckets
[bucket
]->next
;
559 alloc_size
= vop_free_bucket_size(bucket
);
565 ret
= (struct voptype_d
*)ssa_operand_alloc (
566 sizeof (struct voptype_d
) + (alloc_size
- 1) * sizeof (vuse_element_t
));
568 VUSE_VECT_NUM_ELEM (ret
->usev
) = num
;
573 /* This routine makes sure that PTR is in an immediate use list, and makes
574 sure the stmt pointer is set to the current stmt. */
577 set_virtual_use_link (use_operand_p ptr
, tree stmt
)
579 /* fold_stmt may have changed the stmt pointers. */
580 if (ptr
->stmt
!= stmt
)
583 /* If this use isn't in a list, add it to the correct list. */
585 link_imm_use (ptr
, *(ptr
->use
));
589 /* Adds OP to the list of defs after LAST. */
591 static inline def_optype_p
592 add_def_op (tree
*op
, def_optype_p last
)
597 DEF_OP_PTR (new) = op
;
604 /* Adds OP to the list of uses of statement STMT after LAST. */
606 static inline use_optype_p
607 add_use_op (tree stmt
, tree
*op
, use_optype_p last
)
612 USE_OP_PTR (new)->use
= op
;
613 link_imm_use_stmt (USE_OP_PTR (new), *op
, stmt
);
620 /* Return a virtual op pointer with NUM elements which are all initialized to OP
621 and are linked into the immediate uses for STMT. The new vop is appended
624 static inline voptype_p
625 add_vop (tree stmt
, tree op
, int num
, voptype_p prev
)
630 new = alloc_vop (num
);
631 for (x
= 0; x
< num
; x
++)
633 VUSE_OP_PTR (new, x
)->prev
= NULL
;
634 SET_VUSE_OP (new, x
, op
);
635 VUSE_OP_PTR (new, x
)->use
= &new->usev
.uses
[x
].use_var
;
636 link_imm_use_stmt (VUSE_OP_PTR (new, x
), new->usev
.uses
[x
].use_var
, stmt
);
646 /* Adds OP to the list of vuses of statement STMT after LAST, and moves
647 LAST to the new element. */
649 static inline voptype_p
650 add_vuse_op (tree stmt
, tree op
, int num
, voptype_p last
)
652 voptype_p
new = add_vop (stmt
, op
, num
, last
);
653 VDEF_RESULT (new) = NULL_TREE
;
658 /* Adds OP to the list of vdefs of statement STMT after LAST, and moves
659 LAST to the new element. */
661 static inline voptype_p
662 add_vdef_op (tree stmt
, tree op
, int num
, voptype_p last
)
664 voptype_p
new = add_vop (stmt
, op
, num
, last
);
665 VDEF_RESULT (new) = op
;
670 /* Reallocate the virtual operand PTR so that it has NUM_ELEM use slots. ROOT
671 is the head of the operand list it belongs to. */
673 static inline struct voptype_d
*
674 realloc_vop (struct voptype_d
*ptr
, unsigned int num_elem
,
675 struct voptype_d
**root
)
679 struct voptype_d
*ret
, *tmp
;
681 if (VUSE_VECT_NUM_ELEM (ptr
->usev
) == num_elem
)
684 val
= VUSE_OP (ptr
, 0);
685 if (TREE_CODE (val
) == SSA_NAME
)
686 val
= SSA_NAME_VAR (val
);
688 stmt
= USE_STMT (VUSE_OP_PTR (ptr
, 0));
690 /* Delink all the existing uses. */
691 for (x
= 0; x
< VUSE_VECT_NUM_ELEM (ptr
->usev
); x
++)
693 use_operand_p use_p
= VUSE_OP_PTR (ptr
, x
);
694 delink_imm_use (use_p
);
697 /* If we want less space, simply use this one, and shrink the size. */
698 if (VUSE_VECT_NUM_ELEM (ptr
->usev
) > num_elem
)
700 VUSE_VECT_NUM_ELEM (ptr
->usev
) = num_elem
;
704 /* It is growing. Allocate a new one and replace the old one. */
705 ret
= add_vuse_op (stmt
, val
, num_elem
, ptr
);
707 /* Clear PTR and add its memory to the free list. */
708 lim
= VUSE_VECT_NUM_ELEM (ptr
->usev
);
710 sizeof (struct voptype_d
) + sizeof (vuse_element_t
) * (lim
- 1));
711 add_vop_to_freelist (ptr
);
713 /* Now simply remove the old one. */
721 tmp
!= NULL
&& tmp
->next
!= ptr
;
728 /* The pointer passed in isn't in STMT's VDEF lists. */
733 /* Reallocate the PTR vdef so that it has NUM_ELEM use slots. */
736 realloc_vdef (struct voptype_d
*ptr
, unsigned int num_elem
)
739 struct voptype_d
*ret
;
741 val
= VDEF_RESULT (ptr
);
742 stmt
= USE_STMT (VDEF_OP_PTR (ptr
, 0));
743 ret
= realloc_vop (ptr
, num_elem
, &(VDEF_OPS (stmt
)));
744 VDEF_RESULT (ret
) = val
;
749 /* Reallocate the PTR vuse so that it has NUM_ELEM use slots. */
752 realloc_vuse (struct voptype_d
*ptr
, unsigned int num_elem
)
755 struct voptype_d
*ret
;
757 stmt
= USE_STMT (VUSE_OP_PTR (ptr
, 0));
758 ret
= realloc_vop (ptr
, num_elem
, &(VUSE_OPS (stmt
)));
763 /* Takes elements from build_defs and turns them into def operands of STMT.
764 TODO -- Make build_defs VEC of tree *. */
767 finalize_ssa_defs (tree stmt
)
770 struct def_optype_d new_list
;
771 def_optype_p old_ops
, last
;
772 unsigned int num
= VEC_length (tree
, build_defs
);
774 /* There should only be a single real definition per assignment. */
775 gcc_assert ((stmt
&& TREE_CODE (stmt
) != GIMPLE_MODIFY_STMT
) || num
<= 1);
777 new_list
.next
= NULL
;
780 old_ops
= DEF_OPS (stmt
);
784 /* Check for the common case of 1 def that hasn't changed. */
785 if (old_ops
&& old_ops
->next
== NULL
&& num
== 1
786 && (tree
*) VEC_index (tree
, build_defs
, 0) == DEF_OP_PTR (old_ops
))
789 /* If there is anything in the old list, free it. */
792 old_ops
->next
= gimple_ssa_operands (cfun
)->free_defs
;
793 gimple_ssa_operands (cfun
)->free_defs
= old_ops
;
796 /* If there is anything remaining in the build_defs list, simply emit it. */
797 for ( ; new_i
< num
; new_i
++)
798 last
= add_def_op ((tree
*) VEC_index (tree
, build_defs
, new_i
), last
);
800 /* Now set the stmt's operands. */
801 DEF_OPS (stmt
) = new_list
.next
;
803 #ifdef ENABLE_CHECKING
807 for (ptr
= DEF_OPS (stmt
); ptr
; ptr
= ptr
->next
)
810 gcc_assert (x
== num
);
816 /* Takes elements from build_uses and turns them into use operands of STMT.
817 TODO -- Make build_uses VEC of tree *. */
820 finalize_ssa_uses (tree stmt
)
823 struct use_optype_d new_list
;
824 use_optype_p old_ops
, ptr
, last
;
826 #ifdef ENABLE_CHECKING
829 unsigned num
= VEC_length (tree
, build_uses
);
831 /* If the pointer to the operand is the statement itself, something is
832 wrong. It means that we are pointing to a local variable (the
833 initial call to update_stmt_operands does not pass a pointer to a
835 for (x
= 0; x
< num
; x
++)
836 gcc_assert (*((tree
*)VEC_index (tree
, build_uses
, x
)) != stmt
);
840 new_list
.next
= NULL
;
843 old_ops
= USE_OPS (stmt
);
845 /* If there is anything in the old list, free it. */
848 for (ptr
= old_ops
; ptr
; ptr
= ptr
->next
)
849 delink_imm_use (USE_OP_PTR (ptr
));
850 old_ops
->next
= gimple_ssa_operands (cfun
)->free_uses
;
851 gimple_ssa_operands (cfun
)->free_uses
= old_ops
;
854 /* Now create nodes for all the new nodes. */
855 for (new_i
= 0; new_i
< VEC_length (tree
, build_uses
); new_i
++)
856 last
= add_use_op (stmt
,
857 (tree
*) VEC_index (tree
, build_uses
, new_i
),
860 /* Now set the stmt's operands. */
861 USE_OPS (stmt
) = new_list
.next
;
863 #ifdef ENABLE_CHECKING
866 for (ptr
= USE_OPS (stmt
); ptr
; ptr
= ptr
->next
)
869 gcc_assert (x
== VEC_length (tree
, build_uses
));
875 /* Takes elements from BUILD_VDEFS and turns them into vdef operands of
876 STMT. FIXME, for now VDEF operators should have a single operand
880 finalize_ssa_vdefs (tree stmt
)
883 struct voptype_d new_list
;
884 voptype_p old_ops
, ptr
, last
;
885 stmt_ann_t ann
= stmt_ann (stmt
);
887 /* Set the symbols referenced by STMT. */
888 if (!bitmap_empty_p (build_stores
))
890 if (ann
->operands
.stores
== NULL
)
891 ann
->operands
.stores
= BITMAP_ALLOC (&operands_bitmap_obstack
);
893 bitmap_copy (ann
->operands
.stores
, build_stores
);
896 BITMAP_FREE (ann
->operands
.stores
);
898 /* If aliases have not been computed, do not instantiate a virtual
899 operator on STMT. Initially, we only compute the SSA form on
900 GIMPLE registers. The virtual SSA form is only computed after
901 alias analysis, so virtual operators will remain unrenamed and
902 the verifier will complain. However, alias analysis needs to
903 access symbol load/store information, so we need to compute
905 if (!gimple_aliases_computed_p (cfun
))
908 new_list
.next
= NULL
;
911 old_ops
= VDEF_OPS (stmt
);
913 while (old_ops
&& new_i
< VEC_length (tree
, build_vdefs
))
915 tree op
= VEC_index (tree
, build_vdefs
, new_i
);
916 unsigned new_uid
= get_name_decl (op
);
917 unsigned old_uid
= get_name_decl (VDEF_RESULT (old_ops
));
919 /* FIXME, for now each VDEF operator should have at most one
920 operand in their RHS. */
921 gcc_assert (VDEF_NUM (old_ops
) == 1);
923 if (old_uid
== new_uid
)
925 /* If the symbols are the same, reuse the existing operand. */
926 last
->next
= old_ops
;
928 old_ops
= old_ops
->next
;
930 set_virtual_use_link (VDEF_OP_PTR (last
, 0), stmt
);
933 else if (old_uid
< new_uid
)
935 /* If old is less than new, old goes to the free list. */
937 delink_imm_use (VDEF_OP_PTR (old_ops
, 0));
938 next
= old_ops
->next
;
939 add_vop_to_freelist (old_ops
);
944 /* This is a new operand. */
945 last
= add_vdef_op (stmt
, op
, 1, last
);
950 /* If there is anything remaining in BUILD_VDEFS, simply emit it. */
951 for ( ; new_i
< VEC_length (tree
, build_vdefs
); new_i
++)
952 last
= add_vdef_op (stmt
, VEC_index (tree
, build_vdefs
, new_i
), 1, last
);
954 /* If there is anything in the old list, free it. */
957 for (ptr
= old_ops
; ptr
; ptr
= last
)
960 delink_imm_use (VDEF_OP_PTR (ptr
, 0));
961 add_vop_to_freelist (ptr
);
965 /* Now set STMT's operands. */
966 VDEF_OPS (stmt
) = new_list
.next
;
968 #ifdef ENABLE_CHECKING
971 for (ptr
= VDEF_OPS (stmt
); ptr
; ptr
= ptr
->next
)
974 gcc_assert (x
== VEC_length (tree
, build_vdefs
));
980 /* Takes elements from BUILD_VUSES and turns them into VUSE operands of
984 finalize_ssa_vuse_ops (tree stmt
)
986 unsigned new_i
, old_i
;
987 voptype_p old_ops
, last
;
988 VEC(tree
,heap
) *new_ops
;
991 /* Set the symbols referenced by STMT. */
992 ann
= stmt_ann (stmt
);
993 if (!bitmap_empty_p (build_loads
))
995 if (ann
->operands
.loads
== NULL
)
996 ann
->operands
.loads
= BITMAP_ALLOC (&operands_bitmap_obstack
);
998 bitmap_copy (ann
->operands
.loads
, build_loads
);
1001 BITMAP_FREE (ann
->operands
.loads
);
1003 /* If aliases have not been computed, do not instantiate a virtual
1004 operator on STMT. Initially, we only compute the SSA form on
1005 GIMPLE registers. The virtual SSA form is only computed after
1006 alias analysis, so virtual operators will remain unrenamed and
1007 the verifier will complain. However, alias analysis needs to
1008 access symbol load/store information, so we need to compute
1010 if (!gimple_aliases_computed_p (cfun
))
1013 /* STMT should have at most one VUSE operator. */
1014 old_ops
= VUSE_OPS (stmt
);
1015 gcc_assert (old_ops
== NULL
|| old_ops
->next
== NULL
);
1020 && old_i
< VUSE_NUM (old_ops
)
1021 && new_i
< VEC_length (tree
, build_vuses
))
1023 tree new_op
= VEC_index (tree
, build_vuses
, new_i
);
1024 tree old_op
= VUSE_OP (old_ops
, old_i
);
1025 unsigned new_uid
= get_name_decl (new_op
);
1026 unsigned old_uid
= get_name_decl (old_op
);
1028 if (old_uid
== new_uid
)
1030 /* If the symbols are the same, reuse the existing operand. */
1031 VEC_safe_push (tree
, heap
, new_ops
, old_op
);
1035 else if (old_uid
< new_uid
)
1037 /* If OLD_UID is less than NEW_UID, the old operand has
1038 disappeared, skip to the next old operand. */
1043 /* This is a new operand. */
1044 VEC_safe_push (tree
, heap
, new_ops
, new_op
);
1049 /* If there is anything remaining in the build_vuses list, simply emit it. */
1050 for ( ; new_i
< VEC_length (tree
, build_vuses
); new_i
++)
1051 VEC_safe_push (tree
, heap
, new_ops
, VEC_index (tree
, build_vuses
, new_i
));
1053 /* If there is anything in the old list, free it. */
1056 for (old_i
= 0; old_i
< VUSE_NUM (old_ops
); old_i
++)
1057 delink_imm_use (VUSE_OP_PTR (old_ops
, old_i
));
1058 add_vop_to_freelist (old_ops
);
1059 VUSE_OPS (stmt
) = NULL
;
1062 /* If there are any operands, instantiate a VUSE operator for STMT. */
1068 last
= add_vuse_op (stmt
, NULL
, VEC_length (tree
, new_ops
), NULL
);
1070 for (i
= 0; VEC_iterate (tree
, new_ops
, i
, op
); i
++)
1071 SET_USE (VUSE_OP_PTR (last
, (int) i
), op
);
1073 VUSE_OPS (stmt
) = last
;
1076 #ifdef ENABLE_CHECKING
1080 if (VUSE_OPS (stmt
))
1082 gcc_assert (VUSE_OPS (stmt
)->next
== NULL
);
1083 x
= VUSE_NUM (VUSE_OPS (stmt
));
1088 gcc_assert (x
== VEC_length (tree
, build_vuses
));
1093 /* Return a new VUSE operand vector for STMT. */
1096 finalize_ssa_vuses (tree stmt
)
1098 unsigned num
, num_vdefs
;
1099 unsigned vuse_index
;
1101 /* Remove superfluous VUSE operands. If the statement already has a
1102 VDEF operator for a variable 'a', then a VUSE for 'a' is not
1103 needed because VDEFs imply a VUSE of the variable. For instance,
1104 suppose that variable 'a' is pointed-to by p and q:
1110 The VUSE <a_2> is superfluous because it is implied by the
1112 num
= VEC_length (tree
, build_vuses
);
1113 num_vdefs
= VEC_length (tree
, build_vdefs
);
1115 if (num
> 0 && num_vdefs
> 0)
1116 for (vuse_index
= 0; vuse_index
< VEC_length (tree
, build_vuses
); )
1119 vuse
= VEC_index (tree
, build_vuses
, vuse_index
);
1120 if (TREE_CODE (vuse
) != SSA_NAME
)
1122 var_ann_t ann
= var_ann (vuse
);
1123 ann
->in_vuse_list
= 0;
1124 if (ann
->in_vdef_list
)
1126 VEC_ordered_remove (tree
, build_vuses
, vuse_index
);
1133 finalize_ssa_vuse_ops (stmt
);
1137 /* Clear the in_list bits and empty the build array for VDEFs and
1141 cleanup_build_arrays (void)
1146 for (i
= 0; VEC_iterate (tree
, build_vdefs
, i
, t
); i
++)
1147 if (TREE_CODE (t
) != SSA_NAME
)
1148 var_ann (t
)->in_vdef_list
= false;
1150 for (i
= 0; VEC_iterate (tree
, build_vuses
, i
, t
); i
++)
1151 if (TREE_CODE (t
) != SSA_NAME
)
1152 var_ann (t
)->in_vuse_list
= false;
1154 VEC_truncate (tree
, build_vdefs
, 0);
1155 VEC_truncate (tree
, build_vuses
, 0);
1156 VEC_truncate (tree
, build_defs
, 0);
1157 VEC_truncate (tree
, build_uses
, 0);
1158 bitmap_clear (build_loads
);
1159 bitmap_clear (build_stores
);
1163 /* Finalize all the build vectors, fill the new ones into INFO. */
1166 finalize_ssa_stmt_operands (tree stmt
)
1168 finalize_ssa_defs (stmt
);
1169 finalize_ssa_uses (stmt
);
1170 finalize_ssa_vdefs (stmt
);
1171 finalize_ssa_vuses (stmt
);
1172 cleanup_build_arrays ();
1176 /* Start the process of building up operands vectors in INFO. */
1179 start_ssa_stmt_operands (void)
1181 gcc_assert (VEC_length (tree
, build_defs
) == 0);
1182 gcc_assert (VEC_length (tree
, build_uses
) == 0);
1183 gcc_assert (VEC_length (tree
, build_vuses
) == 0);
1184 gcc_assert (VEC_length (tree
, build_vdefs
) == 0);
1185 gcc_assert (bitmap_empty_p (build_loads
));
1186 gcc_assert (bitmap_empty_p (build_stores
));
1190 /* Add DEF_P to the list of pointers to operands. */
1193 append_def (tree
*def_p
)
1195 VEC_safe_push (tree
, heap
, build_defs
, (tree
) def_p
);
1199 /* Add USE_P to the list of pointers to operands. */
1202 append_use (tree
*use_p
)
1204 VEC_safe_push (tree
, heap
, build_uses
, (tree
) use_p
);
1208 /* Add VAR to the set of variables that require a VDEF operator. */
1211 append_vdef (tree var
)
1215 if (TREE_CODE (var
) != SSA_NAME
)
1220 /* If VAR belongs to a memory partition, use it instead of VAR. */
1221 mpt
= memory_partition (var
);
1225 /* Don't allow duplicate entries. */
1226 ann
= get_var_ann (var
);
1227 if (ann
->in_vdef_list
)
1230 ann
->in_vdef_list
= true;
1234 sym
= SSA_NAME_VAR (var
);
1236 VEC_safe_push (tree
, heap
, build_vdefs
, var
);
1237 bitmap_set_bit (build_stores
, DECL_UID (sym
));
1241 /* Add VAR to the set of variables that require a VUSE operator. */
1244 append_vuse (tree var
)
1248 if (TREE_CODE (var
) != SSA_NAME
)
1253 /* If VAR belongs to a memory partition, use it instead of VAR. */
1254 mpt
= memory_partition (var
);
1258 /* Don't allow duplicate entries. */
1259 ann
= get_var_ann (var
);
1260 if (ann
->in_vuse_list
|| ann
->in_vdef_list
)
1263 ann
->in_vuse_list
= true;
1267 sym
= SSA_NAME_VAR (var
);
1269 VEC_safe_push (tree
, heap
, build_vuses
, var
);
1270 bitmap_set_bit (build_loads
, DECL_UID (sym
));
1274 /* REF is a tree that contains the entire pointer dereference
1275 expression, if available, or NULL otherwise. ALIAS is the variable
1276 we are asking if REF can access. OFFSET and SIZE come from the
1277 memory access expression that generated this virtual operand. */
1280 access_can_touch_variable (tree ref
, tree alias
, HOST_WIDE_INT offset
,
1283 bool offsetgtz
= offset
> 0;
1284 unsigned HOST_WIDE_INT uoffset
= (unsigned HOST_WIDE_INT
) offset
;
1285 tree base
= ref
? get_base_address (ref
) : NULL
;
1287 /* If ALIAS is .GLOBAL_VAR then the memory reference REF must be
1288 using a call-clobbered memory tag. By definition, call-clobbered
1289 memory tags can always touch .GLOBAL_VAR. */
1290 if (alias
== gimple_global_var (cfun
))
1293 /* If ALIAS is an SFT, it can't be touched if the offset
1294 and size of the access is not overlapping with the SFT offset and
1295 size. This is only true if we are accessing through a pointer
1296 to a type that is the same as SFT_PARENT_VAR. Otherwise, we may
1297 be accessing through a pointer to some substruct of the
1298 structure, and if we try to prune there, we will have the wrong
1299 offset, and get the wrong answer.
1300 i.e., we can't prune without more work if we have something like
1306 const char *byte_op;
1314 foo = &targetm.asm_out.aligned_op;
1317 SFT.1, which represents hi, will have SFT_OFFSET=32 because in
1318 terms of SFT_PARENT_VAR, that is where it is.
1319 However, the access through the foo pointer will be at offset 0. */
1321 && TREE_CODE (alias
) == STRUCT_FIELD_TAG
1323 && TREE_TYPE (base
) == TREE_TYPE (SFT_PARENT_VAR (alias
))
1324 && !overlap_subvar (offset
, size
, alias
, NULL
))
1326 #ifdef ACCESS_DEBUGGING
1327 fprintf (stderr
, "Access to ");
1328 print_generic_expr (stderr
, ref
, 0);
1329 fprintf (stderr
, " may not touch ");
1330 print_generic_expr (stderr
, alias
, 0);
1331 fprintf (stderr
, " in function %s\n", get_name (current_function_decl
));
1336 /* Without strict aliasing, it is impossible for a component access
1337 through a pointer to touch a random variable, unless that
1338 variable *is* a structure or a pointer.
1340 That is, given p->c, and some random global variable b,
1341 there is no legal way that p->c could be an access to b.
1343 Without strict aliasing on, we consider it legal to do something
1346 struct foos { int l; };
1348 static struct foos *getfoo(void);
1351 struct foos *f = getfoo();
1358 static struct foos *getfoo(void)
1359 { return (struct foos *)&foo; }
1361 (taken from 20000623-1.c)
1363 The docs also say/imply that access through union pointers
1364 is legal (but *not* if you take the address of the union member,
1365 i.e. the inverse), such that you can do
1375 U *pretmp = (U*)&rv;
1379 To implement this, we just punt on accesses through union
1383 && flag_strict_aliasing
1384 && TREE_CODE (ref
) != INDIRECT_REF
1386 && (TREE_CODE (base
) != INDIRECT_REF
1387 || TREE_CODE (TREE_TYPE (base
)) != UNION_TYPE
)
1388 && !AGGREGATE_TYPE_P (TREE_TYPE (alias
))
1389 && TREE_CODE (TREE_TYPE (alias
)) != COMPLEX_TYPE
1390 && !var_ann (alias
)->is_heapvar
1391 /* When the struct has may_alias attached to it, we need not to
1393 && get_alias_set (base
))
1395 #ifdef ACCESS_DEBUGGING
1396 fprintf (stderr
, "Access to ");
1397 print_generic_expr (stderr
, ref
, 0);
1398 fprintf (stderr
, " may not touch ");
1399 print_generic_expr (stderr
, alias
, 0);
1400 fprintf (stderr
, " in function %s\n", get_name (current_function_decl
));
1405 /* If the offset of the access is greater than the size of one of
1406 the possible aliases, it can't be touching that alias, because it
1407 would be past the end of the structure. */
1409 && flag_strict_aliasing
1410 && TREE_CODE (ref
) != INDIRECT_REF
1412 && !POINTER_TYPE_P (TREE_TYPE (alias
))
1414 && DECL_SIZE (alias
)
1415 && TREE_CODE (DECL_SIZE (alias
)) == INTEGER_CST
1416 && uoffset
> TREE_INT_CST_LOW (DECL_SIZE (alias
)))
1418 #ifdef ACCESS_DEBUGGING
1419 fprintf (stderr
, "Access to ");
1420 print_generic_expr (stderr
, ref
, 0);
1421 fprintf (stderr
, " may not touch ");
1422 print_generic_expr (stderr
, alias
, 0);
1423 fprintf (stderr
, " in function %s\n", get_name (current_function_decl
));
1432 /* Add VAR to the virtual operands array. FLAGS is as in
1433 get_expr_operands. FULL_REF is a tree that contains the entire
1434 pointer dereference expression, if available, or NULL otherwise.
1435 OFFSET and SIZE come from the memory access expression that
1436 generated this virtual operand. FOR_CLOBBER is true is this is
1437 adding a virtual operand for a call clobber. */
1440 add_virtual_operand (tree var
, stmt_ann_t s_ann
, int flags
,
1441 tree full_ref
, HOST_WIDE_INT offset
,
1442 HOST_WIDE_INT size
, bool for_clobber
)
1444 VEC(tree
,gc
) *aliases
;
1448 sym
= (TREE_CODE (var
) == SSA_NAME
? SSA_NAME_VAR (var
) : var
);
1449 v_ann
= var_ann (sym
);
1451 /* Mark the statement as having memory operands. */
1452 s_ann
->references_memory
= true;
1454 /* Mark statements with volatile operands. Optimizers should back
1455 off from statements having volatile operands. */
1456 if (TREE_THIS_VOLATILE (sym
) && s_ann
)
1457 s_ann
->has_volatile_ops
= true;
1459 /* If the variable cannot be modified and this is a VDEF change
1460 it into a VUSE. This happens when read-only variables are marked
1461 call-clobbered and/or aliased to writable variables. So we only
1462 check that this only happens on non-specific stores.
1464 Note that if this is a specific store, i.e. associated with a
1465 GIMPLE_MODIFY_STMT, then we can't suppress the VDEF, lest we run
1466 into validation problems.
1468 This can happen when programs cast away const, leaving us with a
1469 store to read-only memory. If the statement is actually executed
1470 at runtime, then the program is ill formed. If the statement is
1471 not executed then all is well. At the very least, we cannot ICE. */
1472 if ((flags
& opf_implicit
) && unmodifiable_var_p (var
))
1475 /* The variable is not a GIMPLE register. Add it (or its aliases) to
1476 virtual operands, unless the caller has specifically requested
1477 not to add virtual operands (used when adding operands inside an
1478 ADDR_EXPR expression). */
1479 if (flags
& opf_no_vops
)
1482 aliases
= v_ann
->may_aliases
;
1483 if (aliases
== NULL
)
1485 if (s_ann
&& !gimple_aliases_computed_p (cfun
))
1486 s_ann
->has_volatile_ops
= true;
1487 /* The variable is not aliased or it is an alias tag. */
1488 if (flags
& opf_def
)
1498 /* The variable is aliased. Add its aliases to the virtual
1500 gcc_assert (VEC_length (tree
, aliases
) != 0);
1502 if (flags
& opf_def
)
1504 bool none_added
= true;
1506 for (i
= 0; VEC_iterate (tree
, aliases
, i
, al
); i
++)
1508 if (!access_can_touch_variable (full_ref
, al
, offset
, size
))
1515 /* If the variable is also an alias tag, add a virtual
1516 operand for it, otherwise we will miss representing
1517 references to the members of the variable's alias set.
1518 This fixes the bug in gcc.c-torture/execute/20020503-1.c.
1520 It is also necessary to add bare defs on clobbers for
1521 SMT's, so that bare SMT uses caused by pruning all the
1522 aliases will link up properly with calls. In order to
1523 keep the number of these bare defs we add down to the
1524 minimum necessary, we keep track of which SMT's were used
1525 alone in statement vdefs or VUSEs. */
1526 if (v_ann
->is_aliased
1528 || (TREE_CODE (var
) == SYMBOL_MEMORY_TAG
1536 bool none_added
= true;
1537 for (i
= 0; VEC_iterate (tree
, aliases
, i
, al
); i
++)
1539 if (!access_can_touch_variable (full_ref
, al
, offset
, size
))
1545 /* Similarly, append a virtual uses for VAR itself, when
1546 it is an alias tag. */
1547 if (v_ann
->is_aliased
|| none_added
)
1554 /* Add *VAR_P to the appropriate operand array for S_ANN. FLAGS is as in
1555 get_expr_operands. If *VAR_P is a GIMPLE register, it will be added to
1556 the statement's real operands, otherwise it is added to virtual
1560 add_stmt_operand (tree
*var_p
, stmt_ann_t s_ann
, int flags
)
1565 gcc_assert (SSA_VAR_P (*var_p
) && s_ann
);
1568 sym
= (TREE_CODE (var
) == SSA_NAME
? SSA_NAME_VAR (var
) : var
);
1569 v_ann
= var_ann (sym
);
1571 /* Mark statements with volatile operands. */
1572 if (TREE_THIS_VOLATILE (sym
))
1573 s_ann
->has_volatile_ops
= true;
1575 if (is_gimple_reg (sym
))
1577 /* The variable is a GIMPLE register. Add it to real operands. */
1578 if (flags
& opf_def
)
1584 add_virtual_operand (var
, s_ann
, flags
, NULL_TREE
, 0, -1, false);
1588 /* A subroutine of get_expr_operands to handle INDIRECT_REF,
1589 ALIGN_INDIRECT_REF and MISALIGNED_INDIRECT_REF.
1591 STMT is the statement being processed, EXPR is the INDIRECT_REF
1594 FLAGS is as in get_expr_operands.
1596 FULL_REF contains the full pointer dereference expression, if we
1597 have it, or NULL otherwise.
1599 OFFSET and SIZE are the location of the access inside the
1600 dereferenced pointer, if known.
1602 RECURSE_ON_BASE should be set to true if we want to continue
1603 calling get_expr_operands on the base pointer, and false if
1604 something else will do it for us. */
1607 get_indirect_ref_operands (tree stmt
, tree expr
, int flags
,
1609 HOST_WIDE_INT offset
, HOST_WIDE_INT size
,
1610 bool recurse_on_base
)
1612 tree
*pptr
= &TREE_OPERAND (expr
, 0);
1614 stmt_ann_t s_ann
= stmt_ann (stmt
);
1616 s_ann
->references_memory
= true;
1617 if (s_ann
&& TREE_THIS_VOLATILE (expr
))
1618 s_ann
->has_volatile_ops
= true;
1620 if (SSA_VAR_P (ptr
))
1622 struct ptr_info_def
*pi
= NULL
;
1624 /* If PTR has flow-sensitive points-to information, use it. */
1625 if (TREE_CODE (ptr
) == SSA_NAME
1626 && (pi
= SSA_NAME_PTR_INFO (ptr
)) != NULL
1627 && pi
->name_mem_tag
)
1629 /* PTR has its own memory tag. Use it. */
1630 add_virtual_operand (pi
->name_mem_tag
, s_ann
, flags
,
1631 full_ref
, offset
, size
, false);
1635 /* If PTR is not an SSA_NAME or it doesn't have a name
1636 tag, use its symbol memory tag. */
1639 /* If we are emitting debugging dumps, display a warning if
1640 PTR is an SSA_NAME with no flow-sensitive alias
1641 information. That means that we may need to compute
1644 && TREE_CODE (ptr
) == SSA_NAME
1648 "NOTE: no flow-sensitive alias info for ");
1649 print_generic_expr (dump_file
, ptr
, dump_flags
);
1650 fprintf (dump_file
, " in ");
1651 print_generic_stmt (dump_file
, stmt
, dump_flags
);
1654 if (TREE_CODE (ptr
) == SSA_NAME
)
1655 ptr
= SSA_NAME_VAR (ptr
);
1656 v_ann
= var_ann (ptr
);
1658 if (v_ann
->symbol_mem_tag
)
1659 add_virtual_operand (v_ann
->symbol_mem_tag
, s_ann
, flags
,
1660 full_ref
, offset
, size
, false);
1661 /* Aliasing information is missing; mark statement as volatile so we
1662 won't optimize it out too actively. */
1663 else if (s_ann
&& !gimple_aliases_computed_p (cfun
)
1664 && (flags
& opf_def
))
1665 s_ann
->has_volatile_ops
= true;
1668 else if (TREE_CODE (ptr
) == INTEGER_CST
)
1670 /* If a constant is used as a pointer, we can't generate a real
1671 operand for it but we mark the statement volatile to prevent
1672 optimizations from messing things up. */
1674 s_ann
->has_volatile_ops
= true;
1679 /* Ok, this isn't even is_gimple_min_invariant. Something's broke. */
1683 /* If requested, add a USE operand for the base pointer. */
1684 if (recurse_on_base
)
1685 get_expr_operands (stmt
, pptr
, opf_use
);
1689 /* A subroutine of get_expr_operands to handle TARGET_MEM_REF. */
1692 get_tmr_operands (tree stmt
, tree expr
, int flags
)
1695 HOST_WIDE_INT offset
, size
, maxsize
;
1697 stmt_ann_t s_ann
= stmt_ann (stmt
);
1699 /* This statement references memory. */
1700 s_ann
->references_memory
= 1;
1702 /* First record the real operands. */
1703 get_expr_operands (stmt
, &TMR_BASE (expr
), opf_use
);
1704 get_expr_operands (stmt
, &TMR_INDEX (expr
), opf_use
);
1706 if (TMR_SYMBOL (expr
))
1707 add_to_addressable_set (TMR_SYMBOL (expr
), &s_ann
->addresses_taken
);
1709 tag
= TMR_TAG (expr
);
1712 /* Something weird, so ensure that we will be careful. */
1713 s_ann
->has_volatile_ops
= true;
1719 get_expr_operands (stmt
, &tag
, flags
);
1723 ref
= get_ref_base_and_extent (tag
, &offset
, &size
, &maxsize
);
1724 gcc_assert (ref
!= NULL_TREE
);
1725 svars
= get_subvars_for_var (ref
);
1726 for (sv
= svars
; sv
; sv
= sv
->next
)
1730 if (overlap_subvar (offset
, maxsize
, sv
->var
, &exact
))
1731 add_stmt_operand (&sv
->var
, s_ann
, flags
);
1736 /* Add clobbering definitions for .GLOBAL_VAR or for each of the call
1737 clobbered variables in the function. */
1740 add_call_clobber_ops (tree stmt
, tree callee
)
1744 stmt_ann_t s_ann
= stmt_ann (stmt
);
1745 bitmap not_read_b
, not_written_b
;
1747 /* Functions that are not const, pure or never return may clobber
1748 call-clobbered variables. */
1750 s_ann
->makes_clobbering_call
= true;
1752 /* If we created .GLOBAL_VAR earlier, just use it. See compute_may_aliases
1753 for the heuristic used to decide whether to create .GLOBAL_VAR or not. */
1754 if (gimple_global_var (cfun
))
1756 tree var
= gimple_global_var (cfun
);
1757 add_stmt_operand (&var
, s_ann
, opf_def
);
1761 /* Get info for local and module level statics. There is a bit
1762 set for each static if the call being processed does not read
1763 or write that variable. */
1764 not_read_b
= callee
? ipa_reference_get_not_read_global (callee
) : NULL
;
1765 not_written_b
= callee
? ipa_reference_get_not_written_global (callee
) : NULL
;
1767 /* Add a VDEF operand for every call clobbered variable. */
1768 EXECUTE_IF_SET_IN_BITMAP (gimple_call_clobbered_vars (cfun
), 0, u
, bi
)
1770 tree var
= referenced_var_lookup (u
);
1771 unsigned int escape_mask
= var_ann (var
)->escape_mask
;
1772 tree real_var
= var
;
1776 /* Not read and not written are computed on regular vars, not
1777 subvars, so look at the parent var if this is an SFT. */
1778 if (TREE_CODE (var
) == STRUCT_FIELD_TAG
)
1779 real_var
= SFT_PARENT_VAR (var
);
1781 not_read
= not_read_b
? bitmap_bit_p (not_read_b
,
1782 DECL_UID (real_var
)) : false;
1783 not_written
= not_written_b
? bitmap_bit_p (not_written_b
,
1784 DECL_UID (real_var
)) : false;
1785 gcc_assert (!unmodifiable_var_p (var
));
1787 clobber_stats
.clobbered_vars
++;
1789 /* See if this variable is really clobbered by this function. */
1791 /* Trivial case: Things escaping only to pure/const are not
1792 clobbered by non-pure-const, and only read by pure/const. */
1793 if ((escape_mask
& ~(ESCAPE_TO_PURE_CONST
)) == 0)
1795 tree call
= get_call_expr_in (stmt
);
1796 if (call_expr_flags (call
) & (ECF_CONST
| ECF_PURE
))
1798 add_stmt_operand (&var
, s_ann
, opf_use
);
1799 clobber_stats
.unescapable_clobbers_avoided
++;
1804 clobber_stats
.unescapable_clobbers_avoided
++;
1811 clobber_stats
.static_write_clobbers_avoided
++;
1813 add_stmt_operand (&var
, s_ann
, opf_use
);
1815 clobber_stats
.static_read_clobbers_avoided
++;
1818 add_virtual_operand (var
, s_ann
, opf_def
, NULL
, 0, -1, true);
1823 /* Add VUSE operands for .GLOBAL_VAR or all call clobbered variables in the
1827 add_call_read_ops (tree stmt
, tree callee
)
1831 stmt_ann_t s_ann
= stmt_ann (stmt
);
1834 /* if the function is not pure, it may reference memory. Add
1835 a VUSE for .GLOBAL_VAR if it has been created. See add_referenced_var
1836 for the heuristic used to decide whether to create .GLOBAL_VAR. */
1837 if (gimple_global_var (cfun
))
1839 tree var
= gimple_global_var (cfun
);
1840 add_stmt_operand (&var
, s_ann
, opf_use
);
1844 not_read_b
= callee
? ipa_reference_get_not_read_global (callee
) : NULL
;
1846 /* Add a VUSE for each call-clobbered variable. */
1847 EXECUTE_IF_SET_IN_BITMAP (gimple_call_clobbered_vars (cfun
), 0, u
, bi
)
1849 tree var
= referenced_var (u
);
1850 tree real_var
= var
;
1853 clobber_stats
.readonly_clobbers
++;
1855 /* Not read and not written are computed on regular vars, not
1856 subvars, so look at the parent var if this is an SFT. */
1858 if (TREE_CODE (var
) == STRUCT_FIELD_TAG
)
1859 real_var
= SFT_PARENT_VAR (var
);
1861 not_read
= not_read_b
? bitmap_bit_p (not_read_b
, DECL_UID (real_var
))
1866 clobber_stats
.static_readonly_clobbers_avoided
++;
1870 add_stmt_operand (&var
, s_ann
, opf_use
| opf_implicit
);
1875 /* A subroutine of get_expr_operands to handle CALL_EXPR. */
1878 get_call_expr_operands (tree stmt
, tree expr
)
1881 int call_flags
= call_expr_flags (expr
);
1882 stmt_ann_t ann
= stmt_ann (stmt
);
1884 ann
->references_memory
= true;
1886 /* If aliases have been computed already, add VDEF or VUSE
1887 operands for all the symbols that have been found to be
1889 if (gimple_aliases_computed_p (cfun
)
1890 && !(call_flags
& ECF_NOVOPS
))
1892 /* A 'pure' or a 'const' function never call-clobbers anything.
1893 A 'noreturn' function might, but since we don't return anyway
1894 there is no point in recording that. */
1895 if (TREE_SIDE_EFFECTS (expr
)
1896 && !(call_flags
& (ECF_PURE
| ECF_CONST
| ECF_NORETURN
)))
1897 add_call_clobber_ops (stmt
, get_callee_fndecl (expr
));
1898 else if (!(call_flags
& ECF_CONST
))
1899 add_call_read_ops (stmt
, get_callee_fndecl (expr
));
1902 /* Find uses in the called function. */
1903 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 0), opf_use
);
1905 for (op
= TREE_OPERAND (expr
, 1); op
; op
= TREE_CHAIN (op
))
1906 get_expr_operands (stmt
, &TREE_VALUE (op
), opf_use
);
1908 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 2), opf_use
);
1912 /* Scan operands in the ASM_EXPR stmt referred to in INFO. */
1915 get_asm_expr_operands (tree stmt
)
1919 const char **oconstraints
;
1920 const char *constraint
;
1921 bool allows_mem
, allows_reg
, is_inout
;
1924 s_ann
= stmt_ann (stmt
);
1925 noutputs
= list_length (ASM_OUTPUTS (stmt
));
1926 oconstraints
= (const char **) alloca ((noutputs
) * sizeof (const char *));
1928 /* Gather all output operands. */
1929 for (i
= 0, link
= ASM_OUTPUTS (stmt
); link
; i
++, link
= TREE_CHAIN (link
))
1931 constraint
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link
)));
1932 oconstraints
[i
] = constraint
;
1933 parse_output_constraint (&constraint
, i
, 0, 0, &allows_mem
,
1934 &allows_reg
, &is_inout
);
1936 /* This should have been split in gimplify_asm_expr. */
1937 gcc_assert (!allows_reg
|| !is_inout
);
1939 /* Memory operands are addressable. Note that STMT needs the
1940 address of this operand. */
1941 if (!allows_reg
&& allows_mem
)
1943 tree t
= get_base_address (TREE_VALUE (link
));
1944 if (t
&& DECL_P (t
) && s_ann
)
1945 add_to_addressable_set (t
, &s_ann
->addresses_taken
);
1948 get_expr_operands (stmt
, &TREE_VALUE (link
), opf_def
);
1951 /* Gather all input operands. */
1952 for (link
= ASM_INPUTS (stmt
); link
; link
= TREE_CHAIN (link
))
1954 constraint
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link
)));
1955 parse_input_constraint (&constraint
, 0, 0, noutputs
, 0, oconstraints
,
1956 &allows_mem
, &allows_reg
);
1958 /* Memory operands are addressable. Note that STMT needs the
1959 address of this operand. */
1960 if (!allows_reg
&& allows_mem
)
1962 tree t
= get_base_address (TREE_VALUE (link
));
1963 if (t
&& DECL_P (t
) && s_ann
)
1964 add_to_addressable_set (t
, &s_ann
->addresses_taken
);
1967 get_expr_operands (stmt
, &TREE_VALUE (link
), 0);
1970 /* Clobber all memory and addressable symbols for asm ("" : : : "memory"); */
1971 for (link
= ASM_CLOBBERS (stmt
); link
; link
= TREE_CHAIN (link
))
1972 if (strcmp (TREE_STRING_POINTER (TREE_VALUE (link
)), "memory") == 0)
1977 s_ann
->references_memory
= true;
1979 EXECUTE_IF_SET_IN_BITMAP (gimple_call_clobbered_vars (cfun
), 0, i
, bi
)
1981 tree var
= referenced_var (i
);
1982 add_stmt_operand (&var
, s_ann
, opf_def
| opf_implicit
);
1985 EXECUTE_IF_SET_IN_BITMAP (gimple_addressable_vars (cfun
), 0, i
, bi
)
1987 tree var
= referenced_var (i
);
1989 /* Subvars are explicitly represented in this list, so we
1990 don't need the original to be added to the clobber ops,
1991 but the original *will* be in this list because we keep
1992 the addressability of the original variable up-to-date
1993 to avoid confusing the back-end. */
1994 if (var_can_have_subvars (var
)
1995 && get_subvars_for_var (var
) != NULL
)
1998 add_stmt_operand (&var
, s_ann
, opf_def
| opf_implicit
);
2005 /* Scan operands for the assignment expression EXPR in statement STMT. */
2008 get_modify_stmt_operands (tree stmt
, tree expr
)
2010 /* First get operands from the RHS. */
2011 get_expr_operands (stmt
, &GIMPLE_STMT_OPERAND (expr
, 1), opf_use
);
2013 /* For the LHS, use a regular definition (opf_def) for GIMPLE
2014 registers. If the LHS is a store to memory, we will need
2015 a preserving definition (VDEF).
2017 Preserving definitions are those that modify a part of an
2018 aggregate object for which no subvars have been computed (or the
2019 reference does not correspond exactly to one of them). Stores
2020 through a pointer are also represented with VDEF operators.
2022 We used to distinguish between preserving and killing definitions.
2023 We always emit preserving definitions now. */
2024 get_expr_operands (stmt
, &GIMPLE_STMT_OPERAND (expr
, 0), opf_def
);
2028 /* Recursively scan the expression pointed to by EXPR_P in statement
2029 STMT. FLAGS is one of the OPF_* constants modifying how to
2030 interpret the operands found. */
2033 get_expr_operands (tree stmt
, tree
*expr_p
, int flags
)
2035 enum tree_code code
;
2036 enum tree_code_class
class;
2037 tree expr
= *expr_p
;
2038 stmt_ann_t s_ann
= stmt_ann (stmt
);
2043 code
= TREE_CODE (expr
);
2044 class = TREE_CODE_CLASS (code
);
2049 /* Taking the address of a variable does not represent a
2050 reference to it, but the fact that the statement takes its
2051 address will be of interest to some passes (e.g. alias
2053 add_to_addressable_set (TREE_OPERAND (expr
, 0), &s_ann
->addresses_taken
);
2055 /* If the address is invariant, there may be no interesting
2056 variable references inside. */
2057 if (is_gimple_min_invariant (expr
))
2060 /* Otherwise, there may be variables referenced inside but there
2061 should be no VUSEs created, since the referenced objects are
2062 not really accessed. The only operands that we should find
2063 here are ARRAY_REF indices which will always be real operands
2064 (GIMPLE does not allow non-registers as array indices). */
2065 flags
|= opf_no_vops
;
2066 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 0), flags
);
2070 case STRUCT_FIELD_TAG
:
2071 case SYMBOL_MEMORY_TAG
:
2072 case NAME_MEMORY_TAG
:
2073 add_stmt_operand (expr_p
, s_ann
, flags
);
2082 /* Add the subvars for a variable, if it has subvars, to DEFS
2083 or USES. Otherwise, add the variable itself. Whether it
2084 goes to USES or DEFS depends on the operand flags. */
2085 if (var_can_have_subvars (expr
)
2086 && (svars
= get_subvars_for_var (expr
)))
2089 for (sv
= svars
; sv
; sv
= sv
->next
)
2090 add_stmt_operand (&sv
->var
, s_ann
, flags
);
2093 add_stmt_operand (expr_p
, s_ann
, flags
);
2098 case MISALIGNED_INDIRECT_REF
:
2099 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 1), flags
);
2102 case ALIGN_INDIRECT_REF
:
2104 get_indirect_ref_operands (stmt
, expr
, flags
, NULL_TREE
, 0, -1, true);
2107 case TARGET_MEM_REF
:
2108 get_tmr_operands (stmt
, expr
, flags
);
2112 case ARRAY_RANGE_REF
:
2118 HOST_WIDE_INT offset
, size
, maxsize
;
2121 /* This component reference becomes an access to all of the
2122 subvariables it can touch, if we can determine that, but
2123 *NOT* the real one. If we can't determine which fields we
2124 could touch, the recursion will eventually get to a
2125 variable and add *all* of its subvars, or whatever is the
2126 minimum correct subset. */
2127 ref
= get_ref_base_and_extent (expr
, &offset
, &size
, &maxsize
);
2128 if (SSA_VAR_P (ref
) && get_subvars_for_var (ref
))
2131 subvar_t svars
= get_subvars_for_var (ref
);
2133 for (sv
= svars
; sv
; sv
= sv
->next
)
2137 if (overlap_subvar (offset
, maxsize
, sv
->var
, &exact
))
2139 int subvar_flags
= flags
;
2141 add_stmt_operand (&sv
->var
, s_ann
, subvar_flags
);
2146 flags
|= opf_no_vops
;
2148 else if (TREE_CODE (ref
) == INDIRECT_REF
)
2150 get_indirect_ref_operands (stmt
, ref
, flags
, expr
, offset
,
2152 flags
|= opf_no_vops
;
2155 /* Even if we found subvars above we need to ensure to see
2156 immediate uses for d in s.a[d]. In case of s.a having
2157 a subvar or we would miss it otherwise. */
2158 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 0), flags
);
2160 if (code
== COMPONENT_REF
)
2162 if (s_ann
&& TREE_THIS_VOLATILE (TREE_OPERAND (expr
, 1)))
2163 s_ann
->has_volatile_ops
= true;
2164 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 2), opf_use
);
2166 else if (code
== ARRAY_REF
|| code
== ARRAY_RANGE_REF
)
2168 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 1), opf_use
);
2169 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 2), opf_use
);
2170 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 3), opf_use
);
2176 case WITH_SIZE_EXPR
:
2177 /* WITH_SIZE_EXPR is a pass-through reference to its first argument,
2178 and an rvalue reference to its second argument. */
2179 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 1), opf_use
);
2180 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 0), flags
);
2184 get_call_expr_operands (stmt
, expr
);
2189 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 0), opf_use
);
2190 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 1), opf_use
);
2191 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 2), opf_use
);
2194 case GIMPLE_MODIFY_STMT
:
2195 get_modify_stmt_operands (stmt
, expr
);
2200 /* General aggregate CONSTRUCTORs have been decomposed, but they
2201 are still in use as the COMPLEX_EXPR equivalent for vectors. */
2202 constructor_elt
*ce
;
2203 unsigned HOST_WIDE_INT idx
;
2206 VEC_iterate (constructor_elt
, CONSTRUCTOR_ELTS (expr
), idx
, ce
);
2208 get_expr_operands (stmt
, &ce
->value
, opf_use
);
2214 case TRUTH_NOT_EXPR
:
2215 case VIEW_CONVERT_EXPR
:
2217 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 0), flags
);
2220 case TRUTH_AND_EXPR
:
2222 case TRUTH_XOR_EXPR
:
2228 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 0), flags
);
2229 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 1), flags
);
2234 case REALIGN_LOAD_EXPR
:
2236 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 0), flags
);
2237 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 1), flags
);
2238 get_expr_operands (stmt
, &TREE_OPERAND (expr
, 2), flags
);
2257 /* Expressions that make no memory references. */
2261 if (class == tcc_unary
)
2263 if (class == tcc_binary
|| class == tcc_comparison
)
2265 if (class == tcc_constant
|| class == tcc_type
)
2269 /* If we get here, something has gone wrong. */
2270 #ifdef ENABLE_CHECKING
2271 fprintf (stderr
, "unhandled expression in get_expr_operands():\n");
2273 fputs ("\n", stderr
);
2279 /* Parse STMT looking for operands. When finished, the various
2280 build_* operand vectors will have potential operands in them. */
2283 parse_ssa_operands (tree stmt
)
2285 enum tree_code code
;
2287 code
= TREE_CODE (stmt
);
2290 case GIMPLE_MODIFY_STMT
:
2291 get_modify_stmt_operands (stmt
, stmt
);
2295 get_expr_operands (stmt
, &COND_EXPR_COND (stmt
), opf_use
);
2299 get_expr_operands (stmt
, &SWITCH_COND (stmt
), opf_use
);
2303 get_asm_expr_operands (stmt
);
2307 get_expr_operands (stmt
, &TREE_OPERAND (stmt
, 0), opf_use
);
2311 get_expr_operands (stmt
, &GOTO_DESTINATION (stmt
), opf_use
);
2315 get_expr_operands (stmt
, &LABEL_EXPR_LABEL (stmt
), opf_use
);
2319 case CASE_LABEL_EXPR
:
2320 case TRY_CATCH_EXPR
:
2321 case TRY_FINALLY_EXPR
:
2322 case EH_FILTER_EXPR
:
2325 /* These nodes contain no variable references. */
2329 /* Notice that if get_expr_operands tries to use &STMT as the
2330 operand pointer (which may only happen for USE operands), we
2331 will fail in add_stmt_operand. This default will handle
2332 statements like empty statements, or CALL_EXPRs that may
2333 appear on the RHS of a statement or as statements themselves. */
2334 get_expr_operands (stmt
, &stmt
, opf_use
);
2340 /* Create an operands cache for STMT. */
2343 build_ssa_operands (tree stmt
)
2345 stmt_ann_t ann
= get_stmt_ann (stmt
);
2347 /* Initially assume that the statement has no volatile operands and
2348 makes no memory references. */
2349 ann
->has_volatile_ops
= false;
2350 ann
->references_memory
= false;
2351 /* Just clear the bitmap so we don't end up reallocating it over and over. */
2352 if (ann
->addresses_taken
)
2353 bitmap_clear (ann
->addresses_taken
);
2355 start_ssa_stmt_operands ();
2356 parse_ssa_operands (stmt
);
2357 operand_build_sort_virtual (build_vuses
);
2358 operand_build_sort_virtual (build_vdefs
);
2359 finalize_ssa_stmt_operands (stmt
);
2361 if (ann
->addresses_taken
&& bitmap_empty_p (ann
->addresses_taken
))
2362 ann
->addresses_taken
= NULL
;
2363 /* For added safety, assume that statements with volatile operands
2364 also reference memory. */
2365 if (ann
->has_volatile_ops
)
2366 ann
->references_memory
= true;
2370 /* Free any operands vectors in OPS. */
2373 free_ssa_operands (stmt_operands_p ops
)
2375 ops
->def_ops
= NULL
;
2376 ops
->use_ops
= NULL
;
2377 ops
->vdef_ops
= NULL
;
2378 ops
->vuse_ops
= NULL
;
2379 BITMAP_FREE (ops
->loads
);
2380 BITMAP_FREE (ops
->stores
);
2384 /* Get the operands of statement STMT. */
2387 update_stmt_operands (tree stmt
)
2389 stmt_ann_t ann
= get_stmt_ann (stmt
);
2391 /* If update_stmt_operands is called before SSA is initialized, do
2393 if (!ssa_operands_active ())
2396 /* The optimizers cannot handle statements that are nothing but a
2397 _DECL. This indicates a bug in the gimplifier. */
2398 gcc_assert (!SSA_VAR_P (stmt
));
2400 timevar_push (TV_TREE_OPS
);
2402 gcc_assert (ann
->modified
);
2403 build_ssa_operands (stmt
);
2406 timevar_pop (TV_TREE_OPS
);
2410 /* Copies virtual operands from SRC to DST. */
2413 copy_virtual_operands (tree dest
, tree src
)
2416 voptype_p src_vuses
, dest_vuses
;
2417 voptype_p src_vdefs
, dest_vdefs
;
2418 struct voptype_d vuse
;
2419 struct voptype_d vdef
;
2420 stmt_ann_t dest_ann
;
2422 VDEF_OPS (dest
) = NULL
;
2423 VUSE_OPS (dest
) = NULL
;
2425 dest_ann
= get_stmt_ann (dest
);
2426 BITMAP_FREE (dest_ann
->operands
.loads
);
2427 BITMAP_FREE (dest_ann
->operands
.stores
);
2429 if (LOADED_SYMS (src
))
2431 dest_ann
->operands
.loads
= BITMAP_ALLOC (&operands_bitmap_obstack
);
2432 bitmap_copy (dest_ann
->operands
.loads
, LOADED_SYMS (src
));
2435 if (STORED_SYMS (src
))
2437 dest_ann
->operands
.stores
= BITMAP_ALLOC (&operands_bitmap_obstack
);
2438 bitmap_copy (dest_ann
->operands
.stores
, STORED_SYMS (src
));
2441 /* Copy all the VUSE operators and corresponding operands. */
2443 for (src_vuses
= VUSE_OPS (src
); src_vuses
; src_vuses
= src_vuses
->next
)
2445 n
= VUSE_NUM (src_vuses
);
2446 dest_vuses
= add_vuse_op (dest
, NULL_TREE
, n
, dest_vuses
);
2447 for (i
= 0; i
< n
; i
++)
2448 SET_USE (VUSE_OP_PTR (dest_vuses
, i
), VUSE_OP (src_vuses
, i
));
2450 if (VUSE_OPS (dest
) == NULL
)
2451 VUSE_OPS (dest
) = vuse
.next
;
2454 /* Copy all the VDEF operators and corresponding operands. */
2456 for (src_vdefs
= VDEF_OPS (src
); src_vdefs
; src_vdefs
= src_vdefs
->next
)
2458 n
= VUSE_NUM (src_vdefs
);
2459 dest_vdefs
= add_vdef_op (dest
, NULL_TREE
, n
, dest_vdefs
);
2460 VDEF_RESULT (dest_vdefs
) = VDEF_RESULT (src_vdefs
);
2461 for (i
= 0; i
< n
; i
++)
2462 SET_USE (VUSE_OP_PTR (dest_vdefs
, i
), VUSE_OP (src_vdefs
, i
));
2464 if (VDEF_OPS (dest
) == NULL
)
2465 VDEF_OPS (dest
) = vdef
.next
;
2470 /* Specifically for use in DOM's expression analysis. Given a store, we
2471 create an artificial stmt which looks like a load from the store, this can
2472 be used to eliminate redundant loads. OLD_OPS are the operands from the
2473 store stmt, and NEW_STMT is the new load which represents a load of the
2477 create_ssa_artificial_load_stmt (tree new_stmt
, tree old_stmt
)
2481 use_operand_p use_p
;
2484 get_stmt_ann (new_stmt
);
2486 /* Process NEW_STMT looking for operands. */
2487 start_ssa_stmt_operands ();
2488 parse_ssa_operands (new_stmt
);
2490 for (i
= 0; VEC_iterate (tree
, build_vuses
, i
, op
); i
++)
2491 if (TREE_CODE (op
) != SSA_NAME
)
2492 var_ann (op
)->in_vuse_list
= false;
2494 for (i
= 0; VEC_iterate (tree
, build_vuses
, i
, op
); i
++)
2495 if (TREE_CODE (op
) != SSA_NAME
)
2496 var_ann (op
)->in_vdef_list
= false;
2498 /* Remove any virtual operands that were found. */
2499 VEC_truncate (tree
, build_vdefs
, 0);
2500 VEC_truncate (tree
, build_vuses
, 0);
2502 /* For each VDEF on the original statement, we want to create a
2503 VUSE of the VDEF result operand on the new statement. */
2504 FOR_EACH_SSA_TREE_OPERAND (op
, old_stmt
, iter
, SSA_OP_VDEF
)
2507 finalize_ssa_stmt_operands (new_stmt
);
2509 /* All uses in this fake stmt must not be in the immediate use lists. */
2510 FOR_EACH_SSA_USE_OPERAND (use_p
, new_stmt
, iter
, SSA_OP_ALL_USES
)
2511 delink_imm_use (use_p
);
2515 /* Swap operands EXP0 and EXP1 in statement STMT. No attempt is done
2516 to test the validity of the swap operation. */
2519 swap_tree_operands (tree stmt
, tree
*exp0
, tree
*exp1
)
2525 /* If the operand cache is active, attempt to preserve the relative
2526 positions of these two operands in their respective immediate use
2528 if (ssa_operands_active () && op0
!= op1
)
2530 use_optype_p use0
, use1
, ptr
;
2533 /* Find the 2 operands in the cache, if they are there. */
2534 for (ptr
= USE_OPS (stmt
); ptr
; ptr
= ptr
->next
)
2535 if (USE_OP_PTR (ptr
)->use
== exp0
)
2541 for (ptr
= USE_OPS (stmt
); ptr
; ptr
= ptr
->next
)
2542 if (USE_OP_PTR (ptr
)->use
== exp1
)
2548 /* If both uses don't have operand entries, there isn't much we can do
2549 at this point. Presumably we don't need to worry about it. */
2552 tree
*tmp
= USE_OP_PTR (use1
)->use
;
2553 USE_OP_PTR (use1
)->use
= USE_OP_PTR (use0
)->use
;
2554 USE_OP_PTR (use0
)->use
= tmp
;
2558 /* Now swap the data. */
2564 /* Add the base address of REF to the set *ADDRESSES_TAKEN. If
2565 *ADDRESSES_TAKEN is NULL, a new set is created. REF may be
2566 a single variable whose address has been taken or any other valid
2567 GIMPLE memory reference (structure reference, array, etc). If the
2568 base address of REF is a decl that has sub-variables, also add all
2569 of its sub-variables. */
2572 add_to_addressable_set (tree ref
, bitmap
*addresses_taken
)
2577 gcc_assert (addresses_taken
);
2579 /* Note that it is *NOT OKAY* to use the target of a COMPONENT_REF
2580 as the only thing we take the address of. If VAR is a structure,
2581 taking the address of a field means that the whole structure may
2582 be referenced using pointer arithmetic. See PR 21407 and the
2583 ensuing mailing list discussion. */
2584 var
= get_base_address (ref
);
2585 if (var
&& SSA_VAR_P (var
))
2587 if (*addresses_taken
== NULL
)
2588 *addresses_taken
= BITMAP_GGC_ALLOC ();
2590 if (var_can_have_subvars (var
)
2591 && (svars
= get_subvars_for_var (var
)))
2594 for (sv
= svars
; sv
; sv
= sv
->next
)
2596 bitmap_set_bit (*addresses_taken
, DECL_UID (sv
->var
));
2597 TREE_ADDRESSABLE (sv
->var
) = 1;
2602 bitmap_set_bit (*addresses_taken
, DECL_UID (var
));
2603 TREE_ADDRESSABLE (var
) = 1;
2609 /* Scan the immediate_use list for VAR making sure its linked properly.
2610 Return TRUE if there is a problem and emit an error message to F. */
2613 verify_imm_links (FILE *f
, tree var
)
2615 use_operand_p ptr
, prev
, list
;
2618 gcc_assert (TREE_CODE (var
) == SSA_NAME
);
2620 list
= &(SSA_NAME_IMM_USE_NODE (var
));
2621 gcc_assert (list
->use
== NULL
);
2623 if (list
->prev
== NULL
)
2625 gcc_assert (list
->next
== NULL
);
2631 for (ptr
= list
->next
; ptr
!= list
; )
2633 if (prev
!= ptr
->prev
)
2636 if (ptr
->use
== NULL
)
2637 goto error
; /* 2 roots, or SAFE guard node. */
2638 else if (*(ptr
->use
) != var
)
2644 /* Avoid infinite loops. 50,000,000 uses probably indicates a
2646 if (count
++ > 50000000)
2650 /* Verify list in the other direction. */
2652 for (ptr
= list
->prev
; ptr
!= list
; )
2654 if (prev
!= ptr
->next
)
2668 if (ptr
->stmt
&& stmt_modified_p (ptr
->stmt
))
2670 fprintf (f
, " STMT MODIFIED. - <%p> ", (void *)ptr
->stmt
);
2671 print_generic_stmt (f
, ptr
->stmt
, TDF_SLIM
);
2673 fprintf (f
, " IMM ERROR : (use_p : tree - %p:%p)", (void *)ptr
,
2675 print_generic_expr (f
, USE_FROM_PTR (ptr
), TDF_SLIM
);
2681 /* Dump all the immediate uses to FILE. */
2684 dump_immediate_uses_for (FILE *file
, tree var
)
2686 imm_use_iterator iter
;
2687 use_operand_p use_p
;
2689 gcc_assert (var
&& TREE_CODE (var
) == SSA_NAME
);
2691 print_generic_expr (file
, var
, TDF_SLIM
);
2692 fprintf (file
, " : -->");
2693 if (has_zero_uses (var
))
2694 fprintf (file
, " no uses.\n");
2696 if (has_single_use (var
))
2697 fprintf (file
, " single use.\n");
2699 fprintf (file
, "%d uses.\n", num_imm_uses (var
));
2701 FOR_EACH_IMM_USE_FAST (use_p
, iter
, var
)
2703 if (use_p
->stmt
== NULL
&& use_p
->use
== NULL
)
2704 fprintf (file
, "***end of stmt iterator marker***\n");
2706 if (!is_gimple_reg (USE_FROM_PTR (use_p
)))
2707 print_generic_stmt (file
, USE_STMT (use_p
), TDF_VOPS
|TDF_MEMSYMS
);
2709 print_generic_stmt (file
, USE_STMT (use_p
), TDF_SLIM
);
2711 fprintf(file
, "\n");
2715 /* Dump all the immediate uses to FILE. */
2718 dump_immediate_uses (FILE *file
)
2723 fprintf (file
, "Immediate_uses: \n\n");
2724 for (x
= 1; x
< num_ssa_names
; x
++)
2729 dump_immediate_uses_for (file
, var
);
2734 /* Dump def-use edges on stderr. */
2737 debug_immediate_uses (void)
2739 dump_immediate_uses (stderr
);
2743 /* Dump def-use edges on stderr. */
2746 debug_immediate_uses_for (tree var
)
2748 dump_immediate_uses_for (stderr
, var
);
2752 /* Create a new change buffer for the statement pointed by STMT_P and
2753 push the buffer into SCB_STACK. Each change buffer
2754 records state information needed to determine what changed in the
2755 statement. Mainly, this keeps track of symbols that may need to be
2756 put into SSA form, SSA name replacements and other information
2757 needed to keep the SSA form up to date. */
2760 push_stmt_changes (tree
*stmt_p
)
2767 /* It makes no sense to keep track of PHI nodes. */
2768 if (TREE_CODE (stmt
) == PHI_NODE
)
2771 buf
= xmalloc (sizeof *buf
);
2772 memset (buf
, 0, sizeof *buf
);
2774 buf
->stmt_p
= stmt_p
;
2776 if (stmt_references_memory_p (stmt
))
2781 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_VUSE
)
2783 tree sym
= TREE_CODE (op
) == SSA_NAME
? SSA_NAME_VAR (op
) : op
;
2784 if (buf
->loads
== NULL
)
2785 buf
->loads
= BITMAP_ALLOC (NULL
);
2786 bitmap_set_bit (buf
->loads
, DECL_UID (sym
));
2789 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_VDEF
)
2791 tree sym
= TREE_CODE (op
) == SSA_NAME
? SSA_NAME_VAR (op
) : op
;
2792 if (buf
->stores
== NULL
)
2793 buf
->stores
= BITMAP_ALLOC (NULL
);
2794 bitmap_set_bit (buf
->stores
, DECL_UID (sym
));
2798 VEC_safe_push (scb_t
, heap
, scb_stack
, buf
);
2802 /* Given two sets S1 and S2, mark the symbols that differ in S1 and S2
2803 for renaming. The set to mark for renaming is (S1 & ~S2) | (S2 & ~S1). */
2806 mark_difference_for_renaming (bitmap s1
, bitmap s2
)
2808 if (s1
== NULL
&& s2
== NULL
)
2811 if (s1
&& s2
== NULL
)
2812 mark_set_for_renaming (s1
);
2813 else if (s1
== NULL
&& s2
)
2814 mark_set_for_renaming (s2
);
2815 else if (!bitmap_equal_p (s1
, s2
))
2817 bitmap t1
= BITMAP_ALLOC (NULL
);
2818 bitmap t2
= BITMAP_ALLOC (NULL
);
2820 bitmap_and_compl (t1
, s1
, s2
);
2821 bitmap_and_compl (t2
, s2
, s1
);
2822 bitmap_ior_into (t1
, t2
);
2823 mark_set_for_renaming (t1
);
2831 /* Pop the top SCB from SCB_STACK and act on the differences between
2832 what was recorded by push_stmt_changes and the current state of
2836 pop_stmt_changes (tree
*stmt_p
)
2840 bitmap loads
, stores
;
2845 /* It makes no sense to keep track of PHI nodes. */
2846 if (TREE_CODE (stmt
) == PHI_NODE
)
2849 buf
= VEC_pop (scb_t
, scb_stack
);
2850 gcc_assert (stmt_p
== buf
->stmt_p
);
2852 /* Force an operand re-scan on the statement and mark any newly
2853 exposed variables. */
2856 /* Determine whether any memory symbols need to be renamed. If the
2857 sets of loads and stores are different after the statement is
2858 modified, then the affected symbols need to be renamed.
2860 Note that it may be possible for the statement to not reference
2861 memory anymore, but we still need to act on the differences in
2862 the sets of symbols. */
2863 loads
= stores
= NULL
;
2864 if (stmt_references_memory_p (stmt
))
2869 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_VUSE
)
2871 tree sym
= TREE_CODE (op
) == SSA_NAME
? SSA_NAME_VAR (op
) : op
;
2873 loads
= BITMAP_ALLOC (NULL
);
2874 bitmap_set_bit (loads
, DECL_UID (sym
));
2877 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_VDEF
)
2879 tree sym
= TREE_CODE (op
) == SSA_NAME
? SSA_NAME_VAR (op
) : op
;
2881 stores
= BITMAP_ALLOC (NULL
);
2882 bitmap_set_bit (stores
, DECL_UID (sym
));
2886 /* If LOADS is different from BUF->LOADS, the affected
2887 symbols need to be marked for renaming. */
2888 mark_difference_for_renaming (loads
, buf
->loads
);
2890 /* Similarly for STORES and BUF->STORES. */
2891 mark_difference_for_renaming (stores
, buf
->stores
);
2893 /* Mark all the naked GIMPLE register operands for renaming. */
2894 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, iter
, SSA_OP_DEF
|SSA_OP_USE
)
2896 mark_sym_for_renaming (op
);
2898 /* FIXME, need to add more finalizers here. Cleanup EH info,
2899 recompute invariants for address expressions, add
2900 SSA replacement mappings, etc. For instance, given
2901 testsuite/gcc.c-torture/compile/pr16808.c, we fold a statement of
2904 # SMT.4_20 = VDEF <SMT.4_16>
2907 So, the VDEF will disappear, but instead of marking SMT.4 for
2908 renaming it would be far more efficient to establish a
2909 replacement mapping that would replace every reference of
2910 SMT.4_20 with SMT.4_16. */
2912 /* Free memory used by the buffer. */
2913 BITMAP_FREE (buf
->loads
);
2914 BITMAP_FREE (buf
->stores
);
2915 BITMAP_FREE (loads
);
2916 BITMAP_FREE (stores
);
2922 /* Discard the topmost change buffer from SCB_STACK. This is useful
2923 when the caller realized that it did not actually modified the
2924 statement. It avoids the expensive operand re-scan. */
2927 discard_stmt_changes (tree
*stmt_p
)
2932 /* It makes no sense to keep track of PHI nodes. */
2934 if (TREE_CODE (stmt
) == PHI_NODE
)
2937 buf
= VEC_pop (scb_t
, scb_stack
);
2938 gcc_assert (stmt_p
== buf
->stmt_p
);
2940 /* Free memory used by the buffer. */
2941 BITMAP_FREE (buf
->loads
);
2942 BITMAP_FREE (buf
->stores
);
2948 /* Returns true if statement STMT may access memory. */
2951 stmt_references_memory_p (tree stmt
)
2953 if (!gimple_ssa_operands (cfun
)->ops_active
|| TREE_CODE (stmt
) == PHI_NODE
)
2956 return stmt_ann (stmt
)->references_memory
;
2960 /* Return the memory partition tag (MPT) associated with memory
2961 symbol SYM. From a correctness standpoint, memory partitions can
2962 be assigned in any arbitrary fashion as long as this rule is
2963 observed: Given two memory partitions MPT.i and MPT.j, they must
2964 not contain symbols in common.
2966 Memory partitions are used when putting the program into Memory-SSA
2967 form. In particular, in Memory-SSA PHI nodes are not computed for
2968 individual memory symbols. They are computed for memory
2969 partitions. This reduces the amount of PHI nodes in the SSA graph
2970 at the expense of precision (i.e., it makes unrelated stores affect
2973 However, it is possible to increase precision by changing this
2974 partitioning scheme. For instance, if the partitioning scheme is
2975 such that get_mpt_for is the identity function (that is,
2976 get_mpt_for (s) = s), this will result in ultimate precision at the
2977 expense of huge SSA webs.
2979 At the other extreme, a partitioning scheme that groups all the
2980 symbols in the same set results in minimal SSA webs and almost
2981 total loss of precision. */
2984 get_mpt_for (tree sym
)
2988 /* Don't create a new tag unnecessarily. */
2989 mpt
= memory_partition (sym
);
2990 if (mpt
== NULL_TREE
)
2992 mpt
= create_tag_raw (MEMORY_PARTITION_TAG
, TREE_TYPE (sym
), "MPT");
2993 TREE_ADDRESSABLE (mpt
) = 0;
2994 MTAG_GLOBAL (mpt
) = 1;
2995 add_referenced_var (mpt
);
2996 VEC_safe_push (tree
, heap
, gimple_ssa_operands (cfun
)->mpt_table
, mpt
);
2997 MPT_SYMBOLS (mpt
) = BITMAP_ALLOC (&operands_bitmap_obstack
);
2998 set_memory_partition (sym
, mpt
);
3005 /* Dump memory partition information to FILE. */
3008 dump_memory_partitions (FILE *file
)
3011 unsigned long nsyms
;
3014 fprintf (file
, "\nMemory partitions\n\n");
3015 for (i
= 0, npart
= 0, nsyms
= 0;
3016 VEC_iterate (tree
, gimple_ssa_operands (cfun
)->mpt_table
, i
, mpt
);
3021 bitmap syms
= MPT_SYMBOLS (mpt
);
3022 unsigned long n
= bitmap_count_bits (syms
);
3024 fprintf (file
, "#%u: ", i
);
3025 print_generic_expr (file
, mpt
, 0);
3026 fprintf (file
, ": %lu elements: ", n
);
3027 dump_decl_set (file
, syms
);
3033 fprintf (file
, "\n%u memory partitions holding %lu symbols\n", npart
, nsyms
);
3037 /* Dump memory partition information to stderr. */
3040 debug_memory_partitions (void)
3042 dump_memory_partitions (stderr
);